MC68HC908GR16 Datasheet, PDF (179/310 Pages) Motorola, Inc – Microcontrollers

Freescale Semiconductor, Inc.
Enhanced Serial Communications Interface (ESCI) Module
I/O Registers
NOTE:
NOTE:
NOTE:
TE — Transmitter Enable Bit
Setting this read/write bit begins the transmission by sending a preamble of 10
or 11 logic 1s from the transmit shift register to the TxD pin. If software clears
the TE bit, the transmitter completes any transmission in progress before the
TxD returns to the idle condition (logic 1). Clearing and then setting TE during a
transmission queues an idle character to be sent after the character currently
being transmitted. Reset clears the TE bit.
1 = Transmitter enabled
0 = Transmitter disabled
Writing to the TE bit is not allowed when the enable ESCI bit (ENSCI) is clear.
ENSCI is in ESCI control register 1.
RE — Receiver Enable Bit
Setting this read/write bit enables the receiver. Clearing the RE bit disables the
receiver but does not affect receiver interrupt flag bits. Reset clears the RE bit.
1 = Receiver enabled
0 = Receiver disabled
Writing to the RE bit is not allowed when the enable ESCI bit (ENSCI) is clear.
ENSCI is in ESCI control register 1.
RWU — Receiver Wakeup Bit
This read/write bit puts the receiver in a standby state during which receiver
interrupts are disabled. The WAKE bit in SCC1 determines whether an idle input
or an address mark brings the receiver out of the standby state and clears the
RWU bit. Reset clears the RWU bit.
1 = Standby state
0 = Normal operation
SBK — Send Break Bit
Setting and then clearing this read/write bit transmits a break character followed
by a logic 1. The logic 1 after the break character guarantees recognition of a
valid start bit. If SBK remains set, the transmitter continuously transmits break
characters with no logic 1s between them. Reset clears the SBK bit.
1 = Transmit break characters
0 = No break characters being transmitted
Do not toggle the SBK bit immediately after setting the SCTE bit. Toggling SBK
before the preamble begins causes the ESCI to send a break character instead of
a preamble.
MC68HC908GR16 — Rev. 1.0
MOTOROLA
Enhanced Serial Communications Interface (ESCI) Module
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Data Sheet
179